The liver is an animal internal organ that plays a very important role, and is involved in various biological reactions, such as metabolism, detoxication, digestion, energy storage and the like as the functions thereof. The liver has a high regeneration capability as compared with other internal organs, and completely regenerates even if part thereof has been removed by surgery or the like. However, even though a mild liver disease occurs, subjective symptoms may not appear, and a very serious life-threatening condition, such as fatty liver, cirrhosis or the like, may have often been reached when a patient becomes aware of the symptoms. Therefore, liver may be referred to as a silent organ.
Liver diseases are mainly caused by viruses. It is generally known that adult chronic hepatitis may be caused by alcohol consumption. A decrease in liver function has been mainly prevented or ameliorated by dietary restriction or administration of drugs. However, dietary restriction may be accompanied by mental difficulty, and incorrect dietary restriction may cause trophopathy. On the other hand, various drugs, such as glutathione, interferon or the like, have been administrated, but it requires taking account of side effects as well as efficacy thereof. Royal jelly (see Patent Document 1, for example), a plant, such as Viburnum phlebotrichum or the like, and an extract thereof (see Patent Document 2, for example), a Curcumae rhizoma-containing composition (see Patent Document 3, for example), a concentrate prepared from sake (see Patent Document 4, for example), and the like have been also known to be effective for liver diseases.
Patent Document 1: JP-A-2000-336038
Patent Document 2: JP-A-2004-346065
Patent Document 3: JP-A-2005-112846
Patent Document 4: JP-A-2006-306792